devices and methods for fixing defects in the anulus fibrosus (vertebral disc) of a patient are described. The devices include a mesh patch, and first and second suture assemblies, each of which include an anchor and a suture. The anchor has a first portion adapted to be inserted into a bone and a second portion having an opening therethrough. The suture is adapted to be disposed through the opening and has a first end is adapted to couple to the mesh patch. The method of treatment includes inserting the first portion of the first anchor into a cranial vertebra and inserting the second portion of the second anchor into a caudal vertebra. The first ends of the sutures are attached to the mesh patch. The mesh patch is positioned adjacent the defect by pulling on, or applying tension to, the second ends of the sutures.
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14. A device for fixing a defect in an anulus fibrosus surrounding an intervertebral space of a patient, the device comprising:
a mesh patch configured for positioning against the outside surface of an anulus fibrosus so as to cover a defect in an annulus fibrosus;
first and second sutures, each having a first end and a second end; and
first and second anchors, each adapted for insertion into the side wall of a vertebral body adjacent to the intervertebral disc space, wherein the first end of the first suture is coupled to the first anchor and the first end of the second suture is coupled to the second anchor; and
wherein the second ends of the first and second sutures extend over the mesh patch without penetrating the mesh patch, and extend adjacent to one another, and are welded to one another over the mesh patch so as to form a substantially continuous band of suture extending from the first anchor to the second anchor, whereby to overlie the mesh patch and thereby capture the mesh patch to the outside surface of the anulus fibrosus.
21. A device for fixing a defect in an anulus fibrosus surrounding an intervertebral disc space of a patient, the device comprising:
a mesh patch configured for positioning against the outside surface of an anulus fibrosus so as to cover a defect in an anulus fibrosus;
a first anchor configured for insertion into the side wall of a vertebral body adjacent to the intervertebral disc space;
a first suture attached to the first anchor;
a second anchor configured for insertion into the side wall of a vertebral body adjacent to the intervertebral disc space; and
a second suture attached to the second anchor;
the first and second sutures extending over the mesh patch without penetrating the mesh patch, and extending adjacent to one another, and being welded to one another so as to form a substantially continuous band of suture extending from the first anchor to the second anchor and across the mesh patch positioned against the outside surface of the anulus fibrosis, whereby to overlie the mesh patch and thereby capture the mesh patch to the outside surface of the anulus fibrosus.
1. A device for fixing a defect in an anulus fibrosus surrounding an intervertebral disc space of a patient, the device comprising:
a mesh patch configured for positioning against the outside surface of an anulus fibrosus so as to cover a defect in an anulus fibrosus;
a first suture assembly comprising:
a first anchor adapted for insertion into the side wall of a vertebral body adjacent to the intervertebral disc space; and
a first suture having a first end and a second end, wherein the first end of the first suture is coupled to the first anchor; and
a second suture assembly comprising:
a second anchor adapted for insertion into the side wall of a vertebral body adjacent to the intervertebral disc space; and
a second suture having a first end and a second end, wherein the first end of the second suture is coupled to the second anchor;
wherein the second ends of the first and second sutures extend over the mesh patch without penetrating the mesh patch, and extend adjacent to one another, and are welded to one another over the mesh patch so as to form a substantially continuous band of suture extending from the first anchor to the second anchor, whereby to overlie the mesh patch and thereby capture the mesh patch to the outside surface of the anulus fibrosus.
17. A device for fixing a defect in an anulus fibrosus surrounding an intervertebral disc space of a patient, the device comprising:
a mesh patch configured for positioning against the outside surface of an anulus fibrosus so as to cover a defect in an annulus fibrosus;
first, second, third, and fourth sutures, each having a first end and a second end; and
first, second, third, and fourth anchors, each adapted for insertion into the side wall of a vertebral body adjacent to the intervertebral disc space, wherein the first ends of the first, second, third, and fourth sutures are coupled to the first, second, third, and fourth anchors, respectively; and
wherein the second end of the first suture and the second end of the second suture extend over the mesh patch without penetrating the mesh patch, and extend adjacent to one another, and are welded to one another over the mesh patch so as to form a substantially continuous band of suture extending from the first anchor to the second anchor, and further wherein the second end of the third suture and the second end of the fourth suture extend over the mesh patch without penetrating the mesh patch, and extend adjacent to one another, and are welded to one another over the mesh patch so as to form a substantially continuous band of suture extending from the third anchor to the fourth anchor, whereby to overlie the mesh patch and thereby capture the mesh patch to the outside surface of the anulus fibrosus.
2. The device of
a third suture assembly comprising:
a third anchor adapted for insertion into the side wall of a vertebral body adjacent to the intervertebral disc space; and
a third suture having a first end and a second end, wherein the first end is coupled to the third anchor; and
a fourth suture assembly comprising:
a fourth anchor adapted for insertion into the side wall of a vertebral body adjacent to the intervertebral disc space; and
a fourth suture having a first end and a second end, wherein the first end is coupled to the fourth anchor;
wherein the second ends of the third and fourth sutures are welded to one another over the mesh patch so as to form a substantially continuous band of suture extending from the third anchor to the fourth anchor, whereby to capture the mesh patch to the outside surface of the anulus fibrosus.
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This application claims the benefit of U.S. Application Ser. No. 60/808,795, filed May 26, 2006, entitled “Fastening Assemblies for Disc Herniation Repair and Methods of Use.” This application is also related to U.S. Patent Application Nos. 60/748,518, filed Dec. 8, 2005, entitled “Cemented Sutures” and 60/738,833, filed Nov. 21, 2005, entitled “Sub-PLL Annular Repair Methods and Devices.” All of the above-mentioned applications are hereby expressly incorporated by reference in their entirety.
The subject invention resides in methods and apparatus for reconstructing the anulus fibrosus (AF) of a spinal disc and the ligaments of the spine. The invention is particularly well suited to the prevention of extrusion of material or devices placed into the disc space and to the prevention of excessive spinal motion.
The human intervertebral disc is an oval to kidney bean-shaped structure of variable size depending on the location in the spine. The outer portion of the disc is known as the anulus fibrosus (AF). The anulus fibrosus is formed of approximately 10 to 60 fibrous bands or layers. The fibers in the bands alternate their direction of orientation by about 30 degrees between each band. The orientation serves to control vertebral motion (one half of the bands tighten to check motion when the vertebra above or below the disc are turned in either direction).
The anulus fibrosus contains the nucleus pulposus (NP). The nucleus pulposus serves to transmit and dampen axial loads. A high water content (approximately 70-80%) assists the nucleus in this function. The water content has a diurnal variation. The nucleus imbibes water while a person lies recumbent. Nuclear material removed from the body and placed into water will imbibe water swelling to several times its normal size. Activity squeezes fluid from the disc. The nucleus comprises roughly 50% of the entire disc. The nucleus contains cells (chondrocytes and fibrocytes) and proteoglycans (chondroitin sulfate and keratin sulfate). The cell density in the nucleus is on the order of 4,000 cells per microliter.
The intervertebral disc changes or “degenerates” with age. As a person ages, the water content of the disc falls from approximately 85% at birth to approximately 70% in the elderly. The ratio of chondroitin sulfate to keratin sulfate decreases with age, while the ratio of chondroitin 6 sulfate to chondroitin 4 sulfate increases with age. The distinction between the anulus and the nucleus decreases with age. Generally disc degeneration is painless.
Premature or accelerated disc degeneration is known as degenerative disc disease. A large portion of patients suffering from chronic low back pain are thought to have this condition. As the disc degenerates, the nucleus and annulus functions are compromised. The nucleus becomes thinner and less able to handle compression loads. The anulus fibers become redundant as the nucleus shrinks. The redundant annular fibers are less effective in controlling vertebral motion. This disc pathology can result in: 1) bulging of the anulus into the spinal cord or nerves; 2) narrowing of the space between the vertebra where the nerves exit; 3) tears of the anulus as abnormal loads are transmitted to the anulus and the anulus is subjected to excessive motion between vertebra; and 4) disc herniation or extrusion of the nucleus through complete anular tears.
Current surgical treatments for disc degeneration are destructive. One group of procedures, which includes lumbar discectomy, removes the nucleus or a portion of the nucleus. A second group of procedures destroy nuclear material. This group includes Chymopapin (an enzyme) injection, laser discectomy, and thermal therapy (heat treatment to denature proteins). The first two groups of procedures compromise the treated disc. A third group, which includes spinal fusion procedures, either remove the disc or the disc's function by connecting two or more vertebra together with bone. Fusion procedures transmit additional stress to the adjacent discs, which results in premature disc degeneration of the adjacent discs. These destructive procedures lead to acceleration of disc degeneration.
Prosthetic disc replacement offers many advantages. The prosthetic disc attempts to eliminate a patient's pain while preserving the disc's function. Current prosthetic disc implants either replace the nucleus or replace both the nucleus and the annulus. Both types of current procedures remove the degenerated disc component to allow room for the prosthetic component. Although the use of resilient materials has been proposed, the need remains for further improvements in the way in which prosthetic components are incorporated into the disc space to ensure strength and longevity. Such improvements are necessary, since the prosthesis may be subjected to 100,000,000 compression cycles over the life of the implant.
Current nucleus replacements (NRs) may cause lower back pain if too much pressure is applied to the anulus fibrosus. As discussed in co-pending U.S. patent application Ser. No. 10/407,554 and U.S. Pat. No. 6,878,167, the content of each being expressly incorporated herein by reference in their entirety, the posterior portion of the anulus fibrosus has abundant pain fibers.
Herniated nucleus pulposus (HNP) occurs from tears in the anulus fibrosus. The herniated nucleus pulposus often applies pressure on the nerves or spinal cord. Compressed nerves cause back and leg or arm pain. Although a patient's symptoms result primarily from pressure by the nucleus pulposus, the primary pathology lies in the anulus fibrosus.
Surgery for herniated nucleus pulposus, known as microlumbar discectomy (MLD), only addresses the nucleus pulposus. The opening in the anulus fibrosus is enlarged during surgery, further weakening the anulus fibrosus. Surgeons also remove generous amounts of the nucleus pulposus to reduce the risk of extruding additional pieces of nucleus pulposus through the defect in the anulus fibrosus. Although microlumbar discectomy decreases or eliminates a patient's leg or arm pain, the procedure damages weakened discs.
In one aspect of the invention, devices for fixing a defect in the anulus fibrosus of a patient are provided. The devices include a mesh patch, a first suture assembly, and a second suture assembly. The first suture assembly includes a first anchor and a first suture. The first anchor has a first portion adapted to be inserted into a bone and a second portion having an opening therethrough. The first suture has a first end and a second end, wherein the first suture is disposed through the hole in the first anchor and wherein the first end is capable of being coupled to the mesh patch. Similarly, the second suture assembled has a second anchor and a second suture. The second anchor has a first portion adapted to be inserted into a bone and a second portion having an opening therethrough. The second suture has a first end and a second end, wherein the second suture is disposed through the hole in the second anchor and wherein the first end is capable of being coupled to the mesh patch.
The sutures may be attached to the mesh patch by welding the first ends of the first and second sutures to the mesh patch. The ends that are attached to the mesh patch may include an enlarged surface area; e.g., the enlarged surface area may be longer or wider than a diameter of the suture. Alternatively, the first ends of the sutures may include a transverse element adapted to anchor the first ends to the mesh patch. The sutures may be slidably disposed within the opening of its respective anchor. Alternatively, the suture may be fixedly attached to its respective anchor. The device may further include third and fourth suture assemblies, each of which has an anchor and suture as described above. The device may also include an anti-adhesion cover adapted to be connected to the mesh patch.
In another aspect of the invention, a method of treating a defect in a vertebral disc of a patient is described. The method includes the steps of providing a device that includes a mesh patch, a first suture assembly, and a second suture assembly, as described above. The first portion of the first anchor is inserted into a vertebra cranial to the vertebral disc. The first portion of the second anchor is inserted into a vertebra caudal to the vertebral disc. The first ends of the first and second sutures are attached to the mesh patch. The mesh patch is positioned adjacent the defect by pulling on, or applying tension to, the second ends of the first and second sutures. The method may further include the step of placing an anti-adhesion cover adjacent the mesh patch.
The first ends of the first and second sutures may be attached to the mesh patch by welding. Alternatively, the first ends of the sutures may comprise a transverse element and the mesh patch may have openings, and the sutures may be attached to the mesh patch by inserting the first ends of the sutures through the openings such that the transverse elements are positioned on a side of the mesh patch opposite of the second ends of the sutures. For instance, a longitudinal axis of the transverse element may be substantially perpendicular to a longitudinal axis of the suture near the first end. The second ends of the first and second sutures may be anchored, e.g., by attaching the second end of the first suture to the second end of the second suture. In one embodiment, the second ends may be anchored or attached together by welding. Third and fourth suture assemblies may also be provided. The first portion of the third anchor may be inserted into the vertebra cranial to the disc and the first portion of the fourth anchor may be inserted into the vertebra caudal to the disc. The first ends of the third and fourth sutures may be attached to the mesh patch and the mesh patch can then be positioned adjacent the defect by pulling on, or applying tension to, the second ends of the third and fourth sutures.
In another aspect of the invention, a device for fixing a defect in the anulus fibrosus of a patient is described. The device includes a mesh patch, first and second sutures, and first and second anchors. The first and second sutures each have a first end and a second end, wherein the first end is adapted for coupling to the mesh patch. The first and second anchors each have a first portion adapted for insertion into a bone and a second portion having an opening, wherein the opening of the first anchor is adapted to receive the first suture and the opening of the second anchor is adapted to receive the second suture. The device may optionally include third and fourth sutures and third and fourth anchors, similar to the first and second sutures and anchors described above.
The sutures may be attached to the mesh patch by welding the first ends of the first and second sutures to the mesh patch. The ends that are attached to the mesh patch may include an enlarged surface area, e.g., the enlarged surface area may be longer or wider than a diameter of the suture. Alternatively, the first ends of the sutures may include a transverse element adapted to anchor the first ends to the mesh patch. The sutures may be slidably disposed within the opening of its respective anchor. Alternatively, the suture may be fixedly attached to its respective anchor. The device may further include third and fourth suture assemblies, each of which has an anchor and suture as described above. The device may also include an anti-adhesion cover adapted to be connected to the mesh patch.
In another aspect of the invention, a method for treating a defect in a vertebral disc of a patient is described. The method includes providing a device having a mesh patch, first and second sutures, and first and second anchors. The first and second sutures each have a first end and a second end, wherein the first end is capable of being coupled to the mesh patch. The first and second anchors each have a first portion adapted to be inserted into a bone and a second portion having an opening, wherein the first suture is threaded through the opening of the first anchor and the second suture is threaded through the opening of the second anchor. The first portion of the first anchor is inserted into a vertebra cranial to the vertebral disc. The first portion of the second anchor is inserted into a vertebra caudal to the vertebral disc. The first ends of the first and second sutures are attached to the mesh patch. The mesh patch is positioned adjacent the defect by pulling on, or applying tension to, the second end of the first and second sutures. The method may further include the step of placing an anti-adhesion cover adjacent the mesh patch.
The first ends of the first and second sutures may be attached to the mesh patch by welding. Alternatively, the first ends of the sutures may comprise a transverse element and the mesh patch may have openings, and the sutures may be attached to the mesh patch by inserting the first ends of the sutures through the openings such that the transverse elements are positioned on a side of the mesh patch opposite of the second ends of the sutures. For instance, a longitudinal axis of the transverse element may be substantially perpendicular to a longitudinal axis near the first ends. The second ends of the first and second sutures may be anchored, e.g., by attaching the second end of the first suture to the second end of the second suture. In one embodiment, the second ends may be anchored or attached together by welding. Third and fourth sutures and third and fourth anchors may also be provided, similar to the first and second anchors described above. The first portion of the third anchor may be inserted into the vertebra cranial to the disc and the first portion of the fourth anchor may be inserted into the vertebra caudal to the disc. The first ends of the third and fourth sutures may be attached to the mesh patch and the mesh patch can then be positioned adjacent the defect by pulling on, or applying tension to, the second ends of the third and fourth sutures.
In another aspect of the invention, a device for fixing a defect in the anulus fibrosus of a patient is described. The device includes a mesh patch; first, second, third, and fourth sutures; and first, second, third, and fourth anchors. The first, second, third, and fourth sutures each have a first end and a second end, wherein the first end is adapted for coupling to the mesh patch. The first, second, third, and fourth anchors each have a first portion adapted for insertion into a bone and a second portion having an opening, wherein the openings of the first, second, third, and fourth anchors are adapted to receive the first, second, third, and fourth sutures.
Each of the sutures may be attached to the mesh patch by welding the first ends of the first and second sutures to the mesh patch. The ends that are attached to the mesh patch may include an enlarged surface area, e.g., the enlarged surface area may be longer or wider than a diameter of the suture. Alternatively, the first ends of the sutures may include a transverse element adapted to anchor the first ends to the mesh patch. The sutures may be slidably disposed within the opening of its respective anchor. Alternatively, the suture may be fixedly attached to its respective anchor. The device may further include third and fourth suture assemblies, each of which has an anchor and suture as described above. The device may also include an anti-adhesion cover adapted to be connected to the mesh patch.
In another aspect of the invention, a method for treating a defect in a vertebral disc of a patient is described. The method includes providing a device having a mesh patch; first, second, third, and fourth sutures; and first, second, third, and fourth anchors, as described above. The first portions of the first and second anchors are inserted into a vertebra cranial to the vertebral disc. The first portions of the third and fourth anchors are inserted into a vertebra caudal to the vertebral disc. The first ends of the first, second, third, and fourth sutures are attached to the mesh patch. The mesh patch is positioned adjacent the defect by pulling on, or applying tension to, the second end of the first, second, third, and fourth sutures.
The first ends of the first and second sutures may be attached to the mesh patch by welding. Alternatively, the first ends of the sutures may comprise a transverse element and the mesh patch may have openings, and the sutures may be attached to the mesh patch by inserting the first ends of the sutures through the openings such that the transverse elements are positioned on a side of the mesh patch opposite of the second ends of the sutures. For instance, a longitudinal axis of the transverse element may be substantially perpendicular to a longitudinal axis near the first ends. The second ends of the first and second sutures may be anchored, e.g., by attaching the second end of the first suture to the second end of the second suture. In one embodiment, the second ends may be anchored or attached together by welding. Third and fourth sutures and third and fourth anchors may also be provided. The first portion of the third anchor may be inserted into the vertebra cranial to the disc and the first portion of the fourth anchor may be inserted into the vertebra caudal to the disc. The first ends of the third and fourth sutures may be attached to the mesh patch and the mesh patch can then be positioned adjacent the defect by pulling on, or applying tension to, the second ends of the third and fourth sutures.
Materials could be placed into the defective region or regions of the Annulus Fibrosus (AF) to promote healing across the entire thickness of the defective region of the AF. For example, a clot of blood marrow aspirated from the vertebrae or other bone in the skeleton could be injected into and over the defective region of the AF. The marrow aspirate could also be injected into and over the in-growth mesh patch or sheet. The cells of the marrow aspirate could be concentrated using such systems as the “Harvest Select” system by DePuy spine. Alternative materials, such as fibrin glue (“Tisseal”, Baxter), or other bio-glue could be inserted into and/or over the defective region of the AF. Portions of the vertebrae near the defective region of the AF, could be perforated, for example with a 1-2 mm diameter drill bit or bur, to improve the blood supply to the relatively avascular AF. The holes are preferably drilled through the vertebral endplates (VEPs) near the defective region of the AF.
The invention may seal the defective region of the AF to promote healing on one side of the device and to prevent anti-adhesion materials from entering the defective region of the AF. Additionally, anti-adhesion materials such Coseal (Baxter) could be injected over the device.
In use, sutures 101a-d are preferably welded or otherwise attached to mesh patch 110 after threading the anchors 103 into the vertebrae. Sutures 101a-d may be welded or otherwise attached to mesh patch 110 outside surgical wound 108. The break-strength of the weld (or attachment) between the flattened end 102a-d of sutures 101a-d and mesh patch 110 preferably exceeds 22 lbs. Free ends 105a-d of sutures 101a-d may then be pulled in order to bring mesh patch 110 flush against the defect.
Alternatively, flat ends 102a-d of sutures 101a-d may be attached to mesh patch 110 prior to inserting anchors 103, or other fastening members, to the spine. Anchors 103 may be forced into the vertebrae rather than threaded into the vertebrae in the alternative embodiment of the invention. The anchors may include deployable components that lock the anchors into the vertebrae. The anchors or fixation members do not pass through the mesh in either embodiment of the device.
Sutures 101a-d may be attached to mesh patch 110 in numerous ways. As discussed previously, flattened ends 102a-d may be welded to the corners of mesh patch 110 using a welding tool. The materials could be welded with a tool from Axya Medical (Beverly, Mass.). The welding tool could weld one suture at a time to the mesh patch. The mesh could be treated to increase the strength of the weld to the sutures. For example, the mesh could be abraided, treated with acid, or an adhesive material to strengthen the weld. Alternatively, more than one suture could be welded to the mesh patch simultaneously. The ends of the sutures could also be fastened to the mesh in other manners. For example, the ends of the sutures could be passed through holes in the mesh and welded to the sutures to create loops at the ends of the sutures (not shown).
Free ends 105a-d of sutures 101a-d may be held away from the wound site until needed using suture holding instrument 118, which is preferably made of an elastomeric material. Free ends 105a-b of the top two sutures are held in openings 119a-b in the corners of suture holding instrument 118. Free ends 105c-d of the bottom two sutures have not yet been placed into holes 119c-d in the bottom of suture holding instrument 118. Suture holding instrument 118 is designed to allow more movement of sutures 101a-d within holes 119a-d of the device than within slits 120a-d leading to holes 119a-d of the device. Holes 119a-d of the device may accommodate both ends of each suture. Surgeons may use the tool to organize the ends of the sutures during surgical procedures.
In an alternative embodiment (not shown), anti-adhesion cover 115 could be laminated to mesh patch 310. Stiff components 302 from the suture anchors could be passed through eyelets in mesh patch 310 and anti-adhesion cover 115. The second ends of sutures 301a-d could be welded over the combined mesh patch/anti-adhesion cover. The alternative embodiment provides a tighter seal of the disc. The tight seal helps prevent the extrusion of the NP and the escape of liquids, gels, or other therapeutic material that may be placed into the disc. Alternative materials, such as Dual Mesh (W.L. Gore and Associates, Flagstaff, Ariz.), with anti-adhesion and tissue in-growth sides on a single patch component could be used the alternative embodiment of the invention. The second ends of the sutures 301a-d may be welded in various configurations that help seal liquids or gels within the disc. Mesh patches with smaller pores could be also be used to seal the disc. The mesh patch could have variable porosity. For example, the mesh patch could have large pores (about 1000 microns) around the periphery of the mesh patch and small pores (less than about 999 microns to about 3 microns) directly in the center of the mesh. The configuration encourages tissue in-growth over the portion of the device that overlies intact regions of the AF and seals the disc over portion of the device that overlies an aperture or defective regions of the AF. Bio-glues, such as Tisseal, may be placed between the patch and the AF to help seal the disc. Lastly, the anti-adhesion cover may be used without the mesh patch component in embodiments of the invention that are designed to seal the disc.
Although the foregoing invention has, for the purposes of clarity and understanding, been described in some detail by way of illustration and example, it will be obvious that certain changes and modifications may be practiced which will still fall within the scope of the appended claims.
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